Exception if code declares both generic and non generic version of a method

[adrianoc]

class Foo
{
	void M<T>() {}
	void M() {}

	public void Bar() => M<string>();
}

note that this also happens with multiple generic methods:

class Foo
{
	void M<T>() {}
	void M<T,S>() {}	

	public void Bar() => M<string>();
}